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//=============================================================================

//

//      synth_diag.c

//

//      Synthetic target diagnostic output code

//

//=============================================================================

// ####ECOSGPLCOPYRIGHTBEGIN####                                            

// -------------------------------------------                              

// This file is part of eCos, the Embedded Configurable Operating System.   

// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2009 Free Software Foundation, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under    

// the terms of the GNU General Public License as published by the Free     

// Software Foundation; either version 2 or (at your option) any later      

// version.                                                                 

//

// eCos is distributed in the hope that it will be useful, but WITHOUT      

// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    

// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    

// for more details.                                                        

//

// You should have received a copy of the GNU General Public License        

// along with eCos; if not, write to the Free Software Foundation, Inc.,    

// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            

//

// As a special exception, if other files instantiate templates or use      

// macros or inline functions from this file, or you compile this file      

// and link it with other works to produce a work based on this file,       

// this file does not by itself cause the resulting work to be covered by   

// the GNU General Public License. However the source code for this file    

// must still be made available in accordance with section (3) of the GNU   

// General Public License v2.                                               

//

// This exception does not invalidate any other reasons why a work based    

// on this file might be covered by the GNU General Public License.         

// -------------------------------------------                              

// ####ECOSGPLCOPYRIGHTEND####                                              

//=============================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   proven

// Contributors:proven, bartv

// Date:        1998-10-05

// Purpose:     HAL diagnostic output

// Description: Implementations of HAL diagnostic output support.

//

//              There are two possible ways of performing I/O. The first

//              involves simply writing to stdout. This is robust, but

//              has some disadvantages such as the output getting mixed up

//              with gdb output. The second involves sending the data on

//              to the auxiliary, less robust but much more flexible.

//

//              Similarly, input can be handled by reading from stdin or

//              by a suitable device in the auxiliary.

//

//####DESCRIPTIONEND####

//

//=============================================================================

#include <cyg/infra/cyg_type.h>

#include <cyg/hal/hal_diag.h>

#include <cyg/hal/hal_io.h>

#include <cyg/hal/hal_intr.h>

#include <cyg/infra/cyg_ass.h>

//-----------------------------------------------------------------------------

// If the auxiliary exists, hal_diag_init() will try to contact it and

// instantiate a console device. Subsequent console writes will be

// redirected to that device, as long as the auxiliary is up and running.

// If the auxiliary is not being used or has exited, console writes

// will instead go to stdout.

//

// This code also contains an implementation of hal_diag_read_char()

// which is probably not very useful. Currently it works by reading

// from stdin, but no attempt is made to set the tty into raw mode

// or anything like that. 

static int auxiliary_console_id = -1;

void hal_diag_init( void )

{

    if (synth_auxiliary_running) {

        auxiliary_console_id = synth_auxiliary_instantiate("hal/synth/arch", SYNTH_MAKESTRING(CYGPKG_HAL_SYNTH), "console",

                                                      (const char*) 0, (const char*) 0);

    }

}

// Output a single character.

//

// The calling code will output one character at a time. Output

// involves at least one system call, and this is expensive for

// a single character (especially when used in conjunction with

// I/O intensive facilities like unbuffered tracing). Therefore

// this code will buffer lines up to 128 characters before

// doing the I/O.

//

// NOTE: one problem is that there is no support for flushing buffers

// at this level. Therefore if say C library stdio ends up mapped to

// HAL diagnostics I/O then functions like fflush() and setvbuf() will

// not behave the way they should. There is no simple workaround at

// this level, the required information is not available.

void hal_diag_write_char(char c)

{

    static int      diag_index = 0;

    static unsigned char diag_buffer[128];

    int             ints_state;

    CYG_ASSERT(diag_index < 128, "Diagnostic buffer overflow");

    HAL_DISABLE_INTERRUPTS(ints_state);

    diag_buffer[diag_index++] = (unsigned char) c;

    if (('\n' == c) || (128 == diag_index)) {

        if ((-1 != auxiliary_console_id) && synth_auxiliary_running) {

            synth_auxiliary_xchgmsg(auxiliary_console_id, 0, 0, 0, diag_buffer, diag_index, (int *) 0, (unsigned char*) 0, (int *)0, 0);

            diag_index = 0;

        } else {

            int     written;

            unsigned char* next    = diag_buffer;

            while (diag_index > 0) {

                written = cyg_hal_sys_write(1, next, diag_index);

                if (written > 0) {

                    diag_index -= written;

                    next       += written;

                } else if ((-CYG_HAL_SYS_EINTR != written) && (-CYG_HAL_SYS_EAGAIN != written)) {

                    CYG_FAIL("Unexpected error writing to stdout.");

                    diag_index = 0;

                    break;

                }

            }

            CYG_ASSERT(0 == diag_index, "All data should have been written out");

            diag_index = 0;

        }

    }

    HAL_RESTORE_INTERRUPTS(ints_state);

}

// Diagnostic input. It is not clear that this is actually useful,

// input would normally go to gdb rather than to the application. If

// keyboard input really is required then that should be handled via a

// suitable device driver interacting with the auxiliary, not at the

// HAL level. The read syscall will get woken up by the itimer alarm,

// but we don't want to stop reading if that's the case

void hal_diag_read_char(char *c)

{

    int rc;

    do {

        rc = cyg_hal_sys_read(0, c, 1);

    } while ((-CYG_HAL_SYS_EINTR == rc) || (-CYG_HAL_SYS_EAGAIN == rc));

}

//-----------------------------------------------------------------------------

// End of hal_diag.c